Can not delete actions in action editor even with Shift + x
When you delete an action, it still exists in Orphan Data:



Although ther's no O next the action name, it will be removed after saving and reopening the file.

If you want to delete all Orphan Data immediatly, just click the "Purge All" button.

NOTE
If you want any orphan date to have a Fake User and prevent them to be deleted, click on the x: